Oxidative fluorination of iridium metal for urban mining: Kinetic studies

The process of oxidative fluorination of a compact iridium metal has been studied. For this purpose, tetrafluoridobromates(III) of alkali and alkaline-earth metals were chosen as oxidizing agents with numerous advantages. The main results of this work include the kinetic dependencies for the two following processes: 1) interaction of iridium with molten potassium tetrafluoridobromate; and 2) interaction of iridium with a solution of potassium tetrafluoridobromate in liquid bromine trifluoride. In both cases it has been found out that iridium can be transformed into its soluble fluorinated derivative; the reaction with molten potassium tetrafluoridobromate proceeds almost 50 times faster (in comparison to the interaction in BrF3 solution) and can be potentially applied for the practical purposes.